MTFCA Forum

I know a T is a old car,but it just seems mine is to squirrely going down a paved road.
Just to make sure,I decided to check things. I found the pitman arm to be a bit loose,about a turn on the nut.
I gave the front wheel bearings a quarter turn,.Checked everything else, only movement I can find is a little movement of the steering shaft in the bracket,i put a new bushing in it when I assembled the steering so the wear must be on the shaft.
There is no lost motion in the steering,I mean literally a twitch of the steering wheel with the wheels off the floor and the wheels turn.5 to 1 ratio, and a larger wheel than stock. I can putter along slow and no issue but when i try to move along at a speed the T feels like it wants to run, well, I can feel every imperfection in the asphalt and it starts to get squirrely.
I have read a bit about a stabilizer and that looks like a good option. It didn't do this at speed for years but it seems it is getting worse. And I just recently got it "legal" and now this.
Is there a hidden issue I don't know about?

Check the “caster angle “ ! The axle should be leaning back above a 1/2” at each kingpin. Have you checked for looseness of the kingpins?
How about the toein?

Ok,I will read up on those things. Kingpins were replaced,along with bushings when the axle was done.There was also a threaded insert made for the right hand kingpin as the threads were wallered out on it.

Axle lean is due to spring perches correct?
I am fairly certain they are correct but never hurts to look again

Now that you mention it,I am betting toe in is a issue.

I will agree with Les except it sounds like toe out. My sister pulled me backwards one time when my t quit. What a ride, it squirreled all over the place. Backing up the leading edge of the tire is placed on the backside and that side is toed out.

Backing up even moderately quickly in a T can be a handful due to the negative caster going in that direction. I'd think that being towed backwards would be nearly deadly for both driver and transmission.

You don't say what year your car is. The early ones had the axle bolted under the wishbone. On those cars if you hit a curb or a pothole it could bend the spring perches and set the axle to negative castor. So be sure to check for castor by the top of the axle at the spindle being farther back than the bottom of the spindle. Follow the specifications and bend if necessary. It is also a good safety device for those cars to attach a lower wishbone to support the bottom side of the axle. Another thing which can cause problems is a bent frame which can be checked by measuring diagonally from one point at the front of the frame to a point on the opposite rear of the frame. The measurements should be equal. If one direction is longer than the other your frame is bent. This will cause the car to pull to one side. A person following you can see that the back of the car does not follow the front on a straight road. the fix for this is more difficult because the body must be removed and the frame straightened.
Norm

What a ride, it squirreled all over the place.

That's why I suspect most of the folks who talk about backing up a hill when the gas is low have never actually done it.

Once the caster angle is set, [by bending the radius rod]. if the steering is still squirely, you might find a copy of Ted Aschman's "Tinkerin'Tips volume 11 and an article on the Ackerman principle and how it relates to a model T. It makes a T steer very well.

Allan from down under.

Mack, how about posting a couple of pictures of your front axle for us. It is hard to diagnose a problem from just a brief description.

A Model T does take 2 hands on the wheel for driving, but lots of people have been working on and abusing these cars for almost 100 years. An axle mounted backwards is not as uncommon as you may think.

Dennis_Brown wrote: ↑

Fri Feb 24, 2023 8:57 pm

I will agree with Les except it sounds like toe out. My sister pulled me backwards one time when my t quit. What a ride, it squirreled all over the place. Backing up the leading edge of the tire is placed on the backside and that side is toed out.

I agree, I bet you have toe out. A friend of mine experienced the same thing, I drove the car too, and wow. It was like "get to the garage NOW"!! I found it to have almost 1 " of TOE OUT...Good grief Lord only knows how that coulda happened. I got it right on spec and what a difference.

A T will drive calm and steady on a smooth paved or gravel road, IF the Caster and Toe are correct, and IF all the play (backlash) has been taken out of the entire chain of mechanical gears and pivots from the steering wheel to the road. Be sure your Caster direction is correct; I have seen and driven a T with the Caster reversed and it is terrible to drive. There are a surprising number of wear points in the chain of steering components. Be sure to check each of them, and then test the total (video below of a good tight steering system, about 5/16 total play in the steering wheel) Here are some of the steps I took just to rebuild the steering column. There are more potential points with backlash downstream too - all the way to the wheels.

It will be next week before I get the T back in the shop as I have my lawnmowers in the shop to service them for the summer.
I was happy to see the small amount of "play" in the steering, that is about how much I have.Not much.
I am thinking toe in or out is the issue.I remember reading about backward axles and perches and being scared I would put mine in backwards I kept checking it.

Humblej wrote: ↑

Sat Feb 25, 2023 8:28 am

Mack, how about posting a couple of pictures of your front axle for us. It is hard to diagnose a problem from just a brief description.

A Model T does take 2 hands on the wheel for driving, but lots of people have been working on and abusing these cars for almost 100 years. An axle mounted backwards is not as uncommon as you may think.

I don't think it would be the axle itself mounted backwards as the problem, I do believe the "naked" axle is reversible. The problem would stem from having the axle "backwards" with the perches mounted in it, hence making THEM backwards, and thence the castor will be screwed up. An easy fix of course. I still think he has a toe-out issue. Hope he lets us know! Inquiring minds!

A Model T is very stable on the road if the steering parts and chassis are as they should be. My car (roadster) is stable and easy to handle at speeds up to 50 MPH on pavement, even with 20 to 30 MPH crosswinds. It handles well on half-decent unpaved roads, as long as they are not washboarded.
Play in the steering assembly will cause problems, but it is equally important that all alignment and assembly are correct, that wheels and tires are in good shape, and that the entire chassis is in good shape. It is common for parts to be too loose, but binding due to poor lubrication, or any other problem, will also cause steering problems. All parts of the chassis should be properly tightened, from front to rear. It is normal for Model T steering to be unstable when backing up. The way to deal with that is to back up only when necessary, and keep speed to a walk.

Some useful stuff:

https://dauntlessgeezer.com/DG104.html

You mentioned “getting worse”. Does this mean your steering was OK but an issue has arisen? If it was OK then the alignment and castor was OK to begin with and something else is either worn or out of adjustment. Another question would be if you hit something to cause a misalignment.

Dry, rusty springs will give a harsh ride and can affect steering. The steering system needs frequent lubrication, every couple of hundred miles. When oiling all the steering parts, take time to check for any looseness or loose fasteners.

If you have wood wheels, they need to be tight and straight and all hardware related to demountable rims, etc, needs to be tight. I get good results running balloon tires at 27 PSI. Narrow tires need to run at 50 to 60 PSI.

Listen to John, if things were fine previously, but have deteriorated gradually due to wear, it's not likely due to a change in Caster. With the axle on blocks/stands, check/correct toe-in (My prime suspect), and kingpins and all steering linkage ball and socket & hinge points along with wishbone ball and socket and spring perch & shackles. If the pitman arm was loose, recheck the key and keyways, those could be worn and if they are, it will never stay put. The lower steering shaft & bushing will remain loose if the shaft is worn, even if you install n a new bushing. There have been recent posts on building up worn steering shafts.

I would also check steering wheel free-play with front tires on the ground, you will likely have more 'slop' in steering against the added resistance.

I recommend fixing the cause of a problem rather than treating symptoms with steering dampeners and antirattle springs on the spindle arms, etc. YMMV, but good luck getting it corrected, stay safe. jb

If you find and correct any and all issues affecting the steering, you will be delighted by how the car handles.

While all the causes were mentioned above, you really need to have someone help you see whats going on. Start by holding onto the Pit Arm and have someone turn the steering wheel an inch or so. If you feel it then do the same, drag link to tie rod. If anything is worn you would notice it for lack of resistance. If all is tight move on to making the adjustments

Another question that hasn’t been asked is have the tires been changed. If they have and when they were bolted back on the wheel is the rim pulled down evenly all the way around? It can happen that one or two of the bolts were tightened down more on one side than the other. They can all seem tight but you can wind up with a wobbly rim on the wheel if it’s not even all the way around.
And unless you’ve hit something hard I don’t think that castor or misalignment can just happen unless you did. Something else is going on that could have caused it if it is.

You did mention that the pitman arm was loose and you tightened up the nut to make it tighter. But did you see if there was any movement of the pitman are ball inside the tie rod? That’s another place that shouldn’t have any looseness.

The wishbone ball that’s bolted on under the oil pan ball bracket under the the engine can easily be overlooked too. They do get wear in that area.

I will say, it drove better with my white wall tires on it. I put a another set on it and it has drove not so well since.
Allstates with a wider foot print than the others had. No play in the pitman arm ball fitting,I do have 1 of those spring loaded things on there to help make sure it doesn't get sloppy

A wider tire, or one with a wider road contact, might aggravate the effects of misalignment. It would not be any fault in the tire. Ts with "balloon" tires handle very well. New tires, and tires with tread as opposed to the smooth type, would ordinarily give better handling.

Get your service manual out & check the ALL geometry as a start. A bit more axle cant will make for a more stable handling @ speed. I have 5/8" one my roadster pick up. Much more stable @ freeway speeds. There is a trade off of stiffer steering @ low speeds.
Check shackle bushings for wear & a tight spring mount.

Put the axle up on jack stands. Grab a wheel top & bottom. You will find king pin & wheel bearing looseness.
Go to the front, grab both wheels push together & pull apart. This will show drag link & tie rod loose bushings.
Do your toe in test reading a center mark on the tires front & rear sides @ hub level. Past posts pictorially show how.

I also agree with speedytinc that best way to check the front end bushings and tie rod ends is to jack the front end completely OFF THE GROUND and carefully check ALL the moving parts for slack. It will surprise you how just a little looseness in the king pin bushings or the tie rod ends can cause some issues. It’s probably something that’s being overlooked that seems like it’s not much.
You’ll find out what ii is eventually. Good luck